Alpha-lactalbumin is a major whey protein found in mammalian milk, comprising approximately 20-25% of total whey protein in bovine milk. It is a globular protein consisting of 123 amino acid residues with a molecular weight of about 14.2 kDa. It plays a critical role in lactose biosynthesis by acting as a regulatory subunit of the lactose synthase complex in the mammary gland. The protein features four disulfide bonds that stabilize its structure, which includes alpha-helices and beta-sheets. It is highly valued in infant nutrition formulas due to its high tryptophan content and similarity to human milk proteins. Alpha-lactalbumin can bind calcium and other metal ions, influencing its stability and functionality in food applications.